US2590455A - Micrometer height gauge - Google Patents

Description

2 SHEETS-SHEET 1 Filed Feb. 5, 1949 .ivz/f/vrap: Q2/9040 M /rr s/l/alsq H. W. PITTENGER MICROMETER HEIGHT GAUGE March 25, 1952 2 SHEETSSHEET 2 Filed Feb. 3, 1949 readings are invariably-absolutely accu to l'i-i:

' la h dIeW h S Big. 1 is primarily a side elevation of a height Patented Mar. 25, 1952 EIQHZT; GA GE Harold w Pjttcnger; Los Angeles; Galifhassignor cwh t No l an a iamiathar hhm 3, 1.9. sea N 74,292

1*: This ion. r laiesto, oreelsiqh iiisii imehts. and more particularly to gagesf or tured under rigid dimensional re Th p r ular orm. f cl r c Qi. the disclosure is a he ht a e pri in an: p opriat s and. av r eel r lns th an i emicmmeter h projecting arm adapted. to be brought mto cone wet w n upp r suri s oiwQ k. to he meets.- ured, such workto be carried upon thev base of; the structure or 11159 1 othe RD t P representing a, predetermined acc te height, so that accurate measurement max. he had'bv manipulation of the. micrometer adjustment means controlling the positioning of th ing rm with respecttot ewo bei g. measured. In connection t nrehisiqn ins rumen of h type herein i clos t sehes am th all her s. of the gage be carefully'machined an M manufacture provide for an a w 7 sures accurate movements without play tortion in, any position. where y to;

in the infinitesimal tolerances; pemitt to cision work. I have found that pre I u and precision readings. can be. pe ormed and performance maintained'only w I ing surfaces. are of adeq l fi, 6313 1,? ranged. and held in proper relatic and where Wear isv snhstanti eliminated by 63 clusion, ofdust and cuttings. from. the w c'i' surfaces which include threads and surfaces d s posed in sliding contact w 1; one. another.

It is. e or a or "a Qb ji of; y 1.1%: vention toproduce precision gaging instr in which all operative, parts red ring; recisiqn v m t a p er y or anizedo insu e. and. m a r ion. movem n a d where n all, such parts are protected against the entrance of dust, cuttings, grindings and similar fore gn mat:- ter.

More particul r t an ob ect of thifii iiel r tion to provide in a precisionjglaging instrument (01-. ammo) Itis an additional object to provide in such an. instrument means which adequately exclude from the contacting surfaces and threads of the instrument all foreign matter which tends to K wear the contacting surfaces or threads or micrometer scales appearing on the cooperating parts. A related object is to provide in a preci on instrument of the gaging type outer, sleevelilge members disposed in overlapping relation so that they may serve as guard means to exclude foreign matter at all times and under all positions and conditions of adjustment. A further related. object is to provideinan outer protecting.

sleeve or guard casing a Window disposed in front of the micrometer scale, whereby to protect the scale from foreign matter as the parts are moved; during measuring operations and to exclude foreign matter at all times.

Other objects of the invention, and the various features ofnovelty, will become apparent to those skilled the art upon reference to the accompanying drawings and the following specification wherein preferred embodiments of the invention a e dis lo edgage incorporating the improvements of this invention;

' Big. 2 isjavertical section on an enlarged scale 39 of the micrometer head and supporting post of h s n en ion;

Fig. 3 is a vertical sectional detail taken on the line 3 .3 of Fig. 2;

Fig. ,4; is a fragmentary. elevational detail taken 35. epnlq ima l r m e i e 4.-4 of Fig. 2;

' Fig. 5 is an enlarged elevational view of the micrometer head; of Figs. 1 and 2, portions being br ke aw y;

Fig. 6, is a cross-sectional view taken on the 11s fi-fi F e and.

' Fig. '7 is across section takenon the line -1 f i s- 2; a 5 and Fig. s is a cross section corresponding with t t of Fig. 'i-and she ing the locking ball mech- H anism ofFig. 7-in unlockedposition.

Ifhe instrument disclose d comprises a base l0 he. radue i hs bein n e form of nula grooves lfl tapered radially inward to form a sub;- stantia lly V-shaped configuration in cross section for reception of locking means carried by a mi rq hete l hea t t l dab m t u on. he p s '2;- Such qchhis' mean include a k ng l -6: a strewn i l-F 2 7 a 8.- lower nd as, tree pest E2 i secu d h' ba e n a y whi h ppor s. a u ri ht ad ated p s I 2 means of a conventional press fit I8, as indicated in Fig. 3.

The micrometer head l comprises a body member which is in the form of a sleeve provided with an axial bore 20a having a dimension to provide a neat, sliding fit upon the cylindrical surface portions of the post l2 at the opposite ends of such body sleeve 20. To facilitate sliding movement of the body sleeve 20, the latter is relieved through its intermediate portion as indicated at 2|. For the purpose of positioning the locking ball [6 in proper relationship to the annular adjusting grooves 14, the lower end of the body sleeve 20 is provided with a transverse small bore 22 which tangentially intercepts the adjacent axial bore 26a in the body sleeve 20.

The locking ball 16 is normally held in a locking position substantially as illustrated in Fig. 7, one side thereof being in engagement with the converging walls of the respective annular groove I4 and the opposite side bearing against corresponding wall portions of the small bore 22. The ball 16 is urged into its normal operative position of Fig. '7 through the medium of a plunger 23 under influence of a spring 24 disposed about the stem 23a of the plunger 23. The stem 23a is received in a slender bore 25 axially disposed in a thumb screw 26 which is threaded into an enlarged outer end portion of the bore 22.- The opposite end portion of the bore 22 receives a plug 21 which axially receives a plunger 28 having an enlarged end 28a engaging the locking ball l6, and provided at its outer end with a head 29 through which the plunger 28 and its enlargement 28a may be moved to dislodge the ball [6 from looking position by forcing the ball and the opposing plunger 23 against the tension of the springs 24 into the unlocking position illustrated in Fig. 8. As'will be apparent, when the ball I6 has been moved by the plunger 28 to the unlocking position of Fig. 8, the micrometer head l5, including the body sleeve 20, may be moved up and down on the post l2 to bring the locking ball l6 into registry with any one of the annular adjusting grooves l4. Upon release of the plunger head 29, the spring 24 returns the locking ball [6 into the locking position illustrated in Fig. '7. In practice the annular grooves M are accurately spaced apart a predetermined distance, for example one inch, so that the elevation of the micrometer head l5 from the base [0, or any other reference point, may be accurately shown, the inches being numbered on the post l2 as indicated in Fig. 1.

In addition to the body sleeve 20, the micrometer head [5 principally comprises a lead screw sleeve 30 accurately fitted to slide along the accurately machined, smooth outer surface of the body sleeve 20, an internally threaded sleeve-like nut 32 engaging the lead screw thread 30a and rotatably fixed upon the outer end of the body sleeve 20, a gaging arm 33 fixed to the lower end of the lead screw sleeve 30 and projecting laterally from the head l5 to engage upon an upper surface of work being measured, a guard sleeve or dust sleeve 34 fixed to the lower end of the lead screw sleeve 30 and to the inner end of the tically, and a micrometer barrel 36 non-rotatably fixed at its top to the upper end of the nut 32 with its lower, skirt portion depending around the upper end of the outer guard casing or sleeve 351 The outer guard casing is provided at one'sid'e with a vertical slot 35a through which the gaging arm 33 projects and in which it slides vertically. The lower edge of the micrometer barrel 36 is beveled as indicated and provided with a micrometer scale 31 extending annularly around the barrel. The extreme lower edge of the barrel 36 and the bottom of the scale 31 overlie a downward from the top of the guard casing 35.

The accurate fit of the lead screw sleeve 30 upon the outer cylindrical surface of the body sleeve 20 insures accurate positioning at all times of the gaging arm 33, and this construction makes it possible to machine the engaging cylindrical surfaceswith precision which is essential in instruments of this type. Since the lead screw sleeve 30, carrying the gaging arm 33, is required to slide vertically upon the body sleeve 20 without rotation, the latter is provided at one side with a vertically extending key way 44 in which there is received the inner end of an accurately fitted key 45 whose outer portion is embedded in a lower, annular ring section 46 integral with the bottom of the lead screw sleeve 30. The outer end of the key 45 is fixed in the adjacent lower end of the dust sleeve 34, thereby insuring movement of the dust sleeve 34 with the lead screw sleeve 30 and preventing rotation of the dust sleeve 34 with respect to the lead screw sleeve 30 and the body sleeve 20. By reason of engagement of the external threads 30a of the lead screw sleeve 30 with the internal threads 32a of the nut 32, rotation of the nut 32 through the medium of the barrel 36 causes the lead screw 30 and the dust sleeve 34 to slide up and down on the body sleeve 20 and within the outer guard casing 35, such movement being guided by the inner end of the key 45 working in the key way 44. Movement of the outer guard casing 35 with the dust sleeve 34 is prevented by reason of the fact that the lower end of the guard casing 35 is rigidly held on the lower end of the body sleeve 20 through the medium of a press fit between a stepped shoulder 41 of the body sleeve 20 and an inwardly disposed annulus 48 integrally carried by the lower end of the dust sleeve 35.

The previously described rotatable mounting of the internally threaded nut 32 and its micrometer barrel 36 upon the upper end of the body sleeve 20 is such as to prevent axial movement of the nut 32 with respect to the body sleeve 20 and to prevent any movement of the micrometer barrel 36 with respect to the internally threaded nut 32. Such mounting of the barrel 36 upon the nut 32 is secured by means of a rigid press fit'upon the top of the nut 32 as indicated by the contact line 50 in Fig. 2 where the" knurled head portion of the barrel 36 is mounted upon an overhanging head portion 52 of the nut 32, such head portion 52 being provided with a bore rotatably receiving a reduced cylindrical extension 54 of the upper portion of the body sleeve 20. The upper and lower annular edges adjacent the bore through the head portion 52 are grooved to provide shoulders 52a, and these grooves receive anti-friction bearing washers in'the form of upper. and lower bearing rings 55 which are disposed against the respective shoulders 52a. The lower face of the lower bearing ring 55 bears upon an annular shoulder 55 provided at the top of the body sleeve where the latter is stepped annularly inward to produce the reduced extension 54. Thus the head portion 52 of the internally threaded nut 32 is accurately and rotatably positioned and maintained axially with respect to the body sleeve 20. The, lower bearing ring 55 and the head portion 52 of the nut 32 are pressed into proper relationship with the shoulder 56 of the body sleeve 26 through the medium of the upper bearing ring 55 and a lock nut 58 which is threadedly engaged at 59 with the extension 54 of the body sleeve 21!. The locking feature of the nut 53 is provided by an accurately machined, inwardly directed overhanging flange 58a which binds upon the outer extremity of the extension 54 as indicated at '66. Such accurate disposition of the locking nut 58 provides for accurate retention of the threaded nut '32, the bearing ring 55, and also the micrometer barrel 36, upon the top of the body sleeve 20.

From the foregoing, it will be seen that when the knurled, upper portion of the micrometer barrel 36 is grasped and rotated by the operator, such rotation is imparted through the press fit indicated at 59 to the internally threaded nut 32 through its head 52 so that the nut 32 rotates, without axial movement, upon the body sleeve 26. Such rotation causes the threads 32a of the threaded nut 32 to move relatively along the threads 36a of the lead screw sleeve 30, with the result that the lead screw sleeve slides up or down along the body sleeve 29 in accordance with the direction of rotation of the micrometer barrel 36, thereby correspondingly raising or lowering the gaging arm 33 and the dust sleeve 34, such movement being guided by the travel of the key 55 in the key way 44 of the body sleeve 2!). Under these circumstances, the gaging arm 33 slides in the slot a of the outer guard casing 35 and the dust sleeve 34 slides within the outer guard casing 35 so that the vertical scale 38 on the dust sleeve 34 moves behind the window 46 in the guard casing 35 and behind the lower end of the micrometer barrel 36 whereby the lower edge thereof at the bottom of the micrometer scale 37 provides a reference point by which the scale 38 is read. However, if preferred, the reference point for reading the scale 38 may be in the form of a crossline 62 (Fig. 5) formed on the window 40, a vertical line 63 being provided on the window 40 as a reference point for reading the micrometer scale 31.

As previously indicated, the casing arm 33 has its inner end fixed in the annular ring section 46 of the lead screw sleeve 39. This may be accomplished as indicated in Figs. 2 and 4, by forming a downwardlyopening notch 65 in the ring section 46 and brazing the arm 33 in place as indicated at 66. The lower end of the dust sleeve 34 is similarly notched, as indicated in Fig. 4, to receive the gaging arm 33, and these parts similarly may be rigidly connected by brazing as indicated at 81. As best indicated in Fig. 1, the outer end of the gaging arm 33 is adapted to receive any form of gaging head 10 which may include a gaging finger ll projecting outward away from the instrument, such finger H having a portion l2 adapted to overhang the outer end of the gaging arm 33 and to be clamped into p0- sitionby any appropriate means such as the loop clamp I; and thumb screw 14 illustrated.

From the foregoing, it will be apparent that the gaging head l5 which carries the scales 3'! and 38 and their respective parts, and therefore constitutes a micrometer head, is adapted to be bodily raised and lowered upon the post I2 by moving the locking ball I6 to the disengaging position of Fig. 8, and shifting the head [5 to any appropriate height so that the locking ball 16 may be placed in locking position within the selected annular positioning group I4. Dislodgeme'nt of the locking ball [6 is readily effected by pressure upon the head 29 of the plunger 28. Return of the ball It to locking position, as indicated in Fig. 7, is effected through the medium of the spring 24 working upon the opposite plunger 23. Such locked position of the ball 16 is retained by turning the thumb screw 26 to force the plunger 23 into fixed contact with the ball 16, either by compressive collapsing of the spring 24 or by engagement of the end of the bore 25 with the inner end of the stem 23a. The gaging arm 33 and its gaging finger H are then moved into proper contact with the work to be measured, such movement being effected through rotation of the knurled micrometer barrel 36, the reading being then taken from the scales 3'! and 38 and added to the inchmarking appearing on the post [2. Should it be desired to rotate the finger H and the head l5 on the post I2, the ball !6 will travel around in the re-'- spective groove [4 upon unlocking the ball by slight loosening of the screw 26. Otherwise, any key system or the like may be used to prevent rotation of the head l5.

As also will be apparent from the foregoing description, the outer guard casing or sleeve 35 and the dust sleeve 34 Very effectually exclude dust, grindings, cuttings, and other foreign particles from the micrometer threads 3% and 32a of the lead screw sleeve 36 and the internally threaded nut 32, as well as from the sliding contact area between the outer cylindrical surface f the body sleeve 20 and the inner cylindrical surface of the lead screw sleeve 30. As a consequence of these features of construction, a highly accurate precision instrument is provided by means of which accurate gaging may be had over a period of a very long instrument life.

Inasmuch as variations within the scope of the present invention will occur to those skilled this art, it is intended to protect all modifications which fall Within the scope of the patent claims.

I claim as my invention;

1. In combination in a gaging instrument; a post; a body sleeve having a bore providing a close sliding fit on said post; means to bind said body sleeve in predetermined position on said post; a lead screw sleeve having a bore providing a close sliding fit on said body sleeve and provided with external, gaging threads; a gaging arm afiixed to said lead screw sleeve adjacent one endof said body sleeve for movement with said lead screw sleeve, and projecting laterally therefrom; a nut provided with internal threads engaged with said lead screw threads, said nut being rotatably secured upon the other end of said body sleeve against longitudinal movement thereon; a gaging barrel rigidly secured on said nut and disposed therearound in spaced relation thereto; and cooperating micrometer scale means carried by said barrel and said lead screw sleeve.

2. A combination as in claim 1 includinga guard casing fixed v on said one end of said body sleeve around and in spaced relation to said lead screw sleeve and enclosing the scale means of said lead screw sleeve, said guard casing being slotted to pass said arm.

3. A combination as in claim 2 including a dust sleeve fixed to said lead screw sleeve to slide within said guard casing and outside said nut, said dust sleeve carrying a micrometer scale of said lead screw sleeve, and said guard casing having window means to view such micrometer scale.

4.'A combination as in claim 3 wherein the free end of said barrel overlies said window means opposite said micrometer scale.

5. A combination as in claim 1 including a dust sleeve fixedly carried by said lead screw sleeve in spaced relation to said external threads to travel along the outer side of said nut and within said barrel, said dust sleeve carrying the micrometer scale means of said lead screw scale.

6. A combination as in claim 1 including a key connecting said lead screw sleeve with said body sleeve to provide for non-rotary sliding movement thereon.

'7. In combination in a gaging instrument: an elongated body sleeve having an axial bore adapted for a close sliding fit on a supporting post and providing a smooth outer surface; a lead screw sleeve mounted against rotation on said body sleeve adjacent one end and having a central bore providing a close sliding fit on said outer surface of said body sleeve, said lead screw sleeve having external lead screw threads; an overhanging nut rotatably mounted on the other end of said body sleeve and retained thereon against axial movement, said nut having internal threads engaging said sleeve lead screw threads; 5. barrel fixed upon and around said nut and extending into outwardly spaced relationship with certain of said threads; scale means fixed to said lead screw sleeve and providing a micrometer scale cooperating with micrometer scale means on said barrel; and a gaging arm fixed to said lead screw sleeve to move therewith and projecting radially therefrom.

8. A combination as in claim '7 wherein said scale means secured to said lead screw sleeve comprises a dust sleeve surrounding said external threads and extending into operative relationship with the extending portion of said barrel, said dust sleeve carrying said micrometer scale.

9. A combination as in claim 8 including a guard casing fixed on said one end of said body sleeve and extending around said dust sleeve, said casing having an opening receiving said gaging arm and providing for movement of said arm therealong, said casing also having a window adjacent the extending portion of said barrel and its micrometer scale means and overlying a portion of said micrometer scale on said dust sleeve.

10. A combination as in claim '7 including a guard casing fixed on said one end of said body sleeve and extending around said lead screw sleeve and into cooperative relation with said 'barrel, said casing having an opening in which said arm is adapted to move and having a window adjacent said micrometer scale of said lead screw sleeve.

11. A combination as in clairn 7 including guard sleeve means disposed around said lead screw sleeve.

12. In combination in a precision instrument: an elongated body sleeve having an axial bore adapted for a close sliding fit on a supporting post and providing a smooth outer surface; a lead screw sleeve mounted against rotation on said body sleeve adjacent one end and having a central bore providing a close sliding fit on said outer surface of said bodysleeve, said lead screw sleeve having external lead screw threads; an overhanging nut rotatably mounted on the other end of said body sleeve and retained thereon against axial movement, said nut having internal threads engaging said lead screw threads; a barrel fixed upon and around said nut and extending into outwardly spaced relationship with certain of said threads; arm means fixed to said lead screw sleeve and projecting radially therefrom; and guard sleeve means disposed about said threads and extending into cooperative relationship with said extending barrel, said arm means extending through passage means provided by said guard sleeve means.

13. A combination as in claim 12 wherein said guard sleeve means comprises a dust sleeve fixed to said lead screw sleeve and a casing around said dust sleeve and fixed to said body sleeve.

14. In combination in a precision instrument: an elongated body sleeve having an axial bore adapted for a close sliding fit on a supporting post and providing a smooth outer surface; a lead screw sleeve mounted against rotation on said body sleeve adjacent one end and having a central bore providing a close sliding fit on said outer surface of said body sleeve, said lead screw sleeve having external lead screw threads; an overhanging nut rotatably mounted on the other end of said body sleeve and retained thereon against axial movement, said nut having internal threads engaging said lead screw threads; and work-engaging means affixed to and projecting from said lead screw sleeve.

15. In combination in a precision instrument: a post having annular locking grooves therein; a micrometer head comprising a body sleeve slidably mounted on said post and relatively movable gaging means mounted on said body sleeve, said body sleeve having a transverse bore; a locking ball mounted in said transverse bore to engag selectively in said grooves; yielding means engaging said ball to urge the latter into locking position; and movable engaging means movable to force said ball into unlocked position against the tension of said yielding means, said yielding means being a spring-pressed plunger mounted in said bore on one side of said ball and said engaging means being a plunger held in said bore on the other side of said ball and having a portion projecting into accessible position beyond said bore.

16. In combination in a precision instrument: an elongated body sleeve having an axial bore adapted for a close sliding fit on a supporting post and providing a smooth outer surface; a lead screw sleeve mounted against rotation on said body sleeve adjacent one end and having a central bore providing a close sliding fit on said outer surface of said body sleeve, said lead screw sleeve having external lead screw threads; an overhanging nut rotatably mounted on the other end of said body sleeve and retained thereon against axial movement, said nut having inter-.

post and providing a smooth outer surface; a lead screw sleeve mounted against rotation on said body sleeve adjacent one end and having a central bore providing a close sliding fit on said outer surface of said body sleeve, said lead screw sleeve having cexternal lead screw threads; an overhanging nut rotatably mounted on the other end of said body sleeve and retained thereon against axial movement, said nut having internal threads engaging said lead screw threads; guard sleeve means connected to said body sleeve; and guard sleeve means connected to said nut, one of said guardsleeve means overhanging the other to exclude foreign matter.

HAROLD W. PITTENGER.

REFERENCES CITED The following references are of record in the file of this patent:

Number 10 UNITED STATESPATENTS Name Date Russom Sept. 16, 1884 Benemelis Oct, 22, 1918 Priputnevich Jan. 3, 1928 Wheelock Jan. 24, 1928 Kutniak Oct. 25, 1932 Lester Feb. 27, 1934 Walsh Aug. 12, 1941 Nystrom July 18, 1944 FOREIGN PATENTS Country Date Great Britain Nov. 28, 1934

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